Automatic detection of touch plane type

• US 6,611,257 B1
• Filed: 09/29/2000
• Issued: 08/26/2003
• Est. Priority Date: 09/29/2000
• Status: Expired due to Fees

• Current Assignee: Rockwell Technologies, LLC
• Original Assignee: Rockwell Automation Technologies Incorporated (Allen-Bradley Co., Inc.)
• Inventors: Sprecher, Reginald W., Dotson, Gary Dan
• Primary Examiner(s): Saras, Steven
• Assistant Examiner(s): Jorgensen, Leland R.
• Application Number:
  US09/676,127
• Time in Patent Office: 1,061 Days
• Field of Search: 345/173, 345/174, 345/175, 345/176, 345/177, 345/178, 178/18.01, 178/18.02, 178/18.03, 178/18.04, 178/18.05, 178/18.06, 178/18.07, 178/18.09, 178/18.11, 178/19.01, 178/19.02, 178/19.03, 178/19.04, 178/19.05, 178/19.06, 178/19.07, 178/20.01, 178/20.02, 178/20.03, 178/20.04, 315/169.3
• US Class Current: 345/174
• CPC Class Codes: G06F 3/038 Control and interface arrangements therefor, e.g. drivers or device-embedded control circuitry
• CPC Class Codes: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact

Abstract

A method of determining a type of touch plane operator input device comprises sensing the impedance across first and second terminals of a touch plane operator input device to distinguish the touch plane operator input device as being one of at least two different types of touch plane operator input devices. A method of processing an input from a touch plane operator input device comprises determining a first location of a first touch on the touch plane operator input device; determining a second location of a second touch on the touch plane operator input device; comparing the first and second locations to obtain an indication of an amount of difference between the first and second locations; and determining whether the indication of the amount of difference exceeds a predetermined amount. These steps are performed by discrete logic circuitry that provides an event notification to a microprocessor when the indication of the amount of difference exceeds the predetermined amount. An interface circuit for a touch plane operator input device comprises a digital signal processor that includes a data processing path along which data from a touch plane operator input device passes while being processed by the digital signal processor. The interface circuit is capable of processing data from first and second different types of touch plane operator input devices. The data path is a common data processing path that is the same for input data for both of the first and second types of touch plane operator input devices.

Claims

1. A method of determining a type of touch plane operator input device, the method comprising sensing the impedance across first and second terminals of a touch plane operator input device to distinguish the input device as being one of at least two different types of analog resistive touch plane operator input devices, and wherein the at least two different types of analog resistive touch plane operator input devices include at least one of the following types of analog resistive touch plane operator input devices:

a 7-wire analog resistive touch plane operator input device and an 8-wire analog resistive touch plane operator input device.

2. A method according to claim 1, wherein the sensing step comprises placing an analog switch matrix into a plurality of different configurations, the analog switch matrix having first and second terminals that are coupled to the first and second terminals of the touch screen, and wherein the sensing step comprises sensing impedance characteristics of the input device while the analog switch matrix is in the plurality of different configurations.

3. A method according to claim 1, wherein the sensing step comprises placing an analog switch matrix into a plurality of different configurations, the analog switch matrix having first and second terminals that are coupled to the first and second terminals of the input device, the analog switch matrix also being coupled to first and second power supply terminals, and wherein the plurality of different configurations establish different connections between the touch screen and the first and second power supply terminals.

4. A method according to claim 1, wherein the sensing step comprises sensing an open connection between the first and second terminals.

5. A method according to claim 1, wherein the sensing step is performed using a touch plane interface located on a system-on-chip integrated circuit chip, and wherein the integrated circuit chip also has a microprocessor located thereon.

6. A method of determining a type of touch plane operator input device, the method comprising sensing the impedance across first and second terminals of a touch plane operator input device to distinguish the input device as being one of at least two different types of analog resistive touch plane operator input devices, wherein the sensing step distinguishes the input device as being one of at least three of the following types of touch screens:

a 4-wire analog resistive touch plane operator input device, a 5-wire analog resistive touch plane operator input device, a 7-wire analog resistive touch plane operator input device, and an 8-wire analog resistive touch plane operator input device.

7. A method of determining a touch plane type of a touch plane operator input device having a plurality of input/output terminals, comprising:

placing an analog switch matrix into a plurality of different configurations, the analog switch matrix being coupled to the touch plane operator input device, the analog switch matrix receiving an input and selectively supplying the input to the input device based on the configuration of the analog switch matrix;

determining the touch plane type based on the response of the input device to the input in the plurality of different configurations of the analog switch matrix, wherein the touch plane type is determined to be one of at least two different types of analog resistive touch plane operator input devices, and wherein the at least two different types of analog resistive touch plane operator input devices include at least one of the following types of analog resistive touch plane operator input devices;

a 7-wire analog resistive touch plane operator input device and an 8-wire analog resistive touch plane operator input device.

8. A method according to claim 7, wherein the determining step comprises sensing impedance characteristics of the input device between different terminals of the input device.

9. A method according to claim 7, wherein the analog switch matrix is located on an integrated circuit chip, and wherein the integrated circuit chip also has a microprocessor located thereon.

10. A method according to claim 7, wherein the determining step comprises determining that the touch plane type is one of the following types of touch plane operator input devices:

a 4-wire analog resistive touch plane operator input device, a 5-wire analog resistive touch plane operator input device, a 7-wire analog resistive touch plane operator input device, and an 8-wire analog resistive touch plane operator input device.

11. A method according to claim 7, wherein the analog switch matrix comprises at least twelve analog switches that are placed into different on/off states during the placing step.

12. A method according to claim 7, further comprising placing the analog switch matrix into a plurality of additional configurations to test the input device to determine whether the input device is operational.

13. A method according to claim 7, further comprising placing the analog switch matrix into an additional configuration to determine whether the input device is pressed.

14. An interface circuit for a touch plane operator input device, the interface circuit being capable of interfacing to (1) a first type of touch plane operator input device having an X-axis resistive layer and a Y-axis resistive layer, the X-axis layer having first and second X-axis bus bars and the Y-axis layer having first and second Y-axis bus bars, the first type including first, second, third and fourth terminals that are connected to different ones of the first and second X-axis bus bars and the first and second Y-axis bus bars, wherein when a voltage is applied to the first and second X-axis bus bars and the Y-axis layer touches the X-axis layer, a voltage is produced at one or both of the first and second Y-axis bus bars that is indicative of the X-position of the touch, and wherein when a voltage is applied to the first and second Y-axis bus bars and the X-axis layer touches the Y-axis layer, a voltage is produced at one or both of the first and second X-axis bus bars that is indicative of the Y-position of the touch, and (2) a second type of touch plane operator input device having a resistive layer and a wiper layer, the resistive layer comprising first, second, third and fourth input terminals and the wiper layer having a fifth terminal, wherein when voltages are applied to the first, second, third and fourth terminals and the wiper layer touches the resistive layer, a voltage is produced at the fifth terminal that is indicative of the X-position of the touch, and wherein when the polarity of the voltage applied to two of the terminals is reversed, a voltage is produced at the fifth terminal that is indicative of the Y-position of the touch, the interface circuit comprising:

an analog switch matrix, the analog switch matrix including first, second, third, fourth and fifth terminals which are adapted to be operably connected to the first, second, third and fourth terminals of the first type of touch plane operator input device and to the first, second, third, fourth and fifth terminals of the second type of touch plane operator input device, and the programmable analog switch matrix comprising a plurality of switches that define a plurality of different configurations of the programmable switch matrix;

an analog-to-digital converter, wherein if the interface circuit is connected to the first type of touch plane operator input device, then the analog-to-digital converter receives analog input data by way of the analog switch matrix from at least two of the first, second, third and fourth terminals of the first type of touch plane operator input device and digitizes the analog input data to produce digital input data, wherein if the interface circuit is connected to the second type of touch plane operator input device, then the analog-to-digital converter receives analog input data by way of the analog switch matrix from at least one of the first, second, third, fourth and fifth terminals of the second type of touch plane operator input device and digitizes the analog input data to produce digital input data; and

wherein, in the plurality of different configurations, the plurality of different switches establish different connections with the touch plane operator input device to sense impedance characteristics of the touch plane operator input device, thereby permitting the interface circuit to be used to distinguish the touch plane operator input device as being either the first type of touch plane operator input device or the second type of touch plane operator input device; and

wherein the interface circuit is further capable interfacing to a third type of touch plane operator input device, the third type of touch plane operator input device having an X-axis resistive layer and a Y-axis resistive layer, the X-axis layer having first and second X-axis bus bars and the Y-axis layer having first and second Y-axis bus bars, the first type including first, second, third and fourth terminals that are connected to different ones of the first and second X-axis bus bars and the first and second Y-axis bus bars, wherein when a voltage is applied to the first and second X-axis bus bars and the Y-axis layer touches the X-axis layer, a voltage is produced at one or both of the first and second Y-axis bus bars that is indicative of the X-position of the touch, and wherein when a voltage is applied to the first and second Y-axis bus bars and the X-axis layer touches the Y-axis layer, a voltage is produced at one or both of the first and second X-axis bus bars that is indicative of the Y-position of the touch, and wherein the third type further includes a plurality of terminals that provide feedback pertaining to at least two of the voltages at the first and second X-axis bus bars and the first and second Y-axis bus bars.

15. An interface circuit according to claim 14, wherein the interface circuit is further capable of interfacing to a fourth type of touch plane operator input device, the fourth type of touch plane operator input device having a resistive layer and a wiper layer, the resistive layer comprising first, second, third and fourth input terminals and the wiper layer having a fifth terminal, wherein when voltages are applied to the first, second, third and fourth terminals and the wiper layer touches the resistive layer, a voltage is produced at the fifth terminal that is indicative of the X-position of the touch, and wherein when the polarity of the voltage applied to two of the terminals is reversed, a voltage is produced at the fifth terminal that is indicative of the Y-position of the touch, and wherein the fourth type further includes a plurality of terminals that provide feedback pertaining to at least two of the voltages at the first, second, third and fourth terminals.

16. An interface circuit for a touch plane operator input device, the interface circuit being capable of interfacing to (1) a first type of touch plane operator input device having an X-axis resistive layer and a Y-axis resistive layer, the X-axis layer having first and second X-axis bus bars and the Y-axis layer having first and second Y-axis bus bars, the first type including first, second, third and fourth terminals that are connected to different ones of the first and second X-axis bus bars and the first and second Y-axis bus bars, wherein when a voltage is applied to the first and second X-axis bus bars and the Y-axis layer touches the X-axis layer, a voltage is produced at one or both of the first and second Y-axis bus bars that is indicative of the X-position of the touch, and wherein when a voltage is applied to the first and second Y-axis bus bars and the X-axis layer touches the Y-axis layer, a voltage is produced at one or both of the first and second X-axis bus bars that is indicative of the Y-position of the touch, and (2) a second type of touch plane operator input device having a resistive layer and a wiper layer, the resistive layer comprising first, second, third and fourth input terminals and the wiper layer having a fifth terminal, wherein when voltages are applied to the first, second, third and fourth terminals and the wiper layer touches the resistive layer, a voltage is produced at the fifth terminal that is indicative of the X-position of the touch, and wherein when the polarity of the voltage applied to two of the terminals is reversed, a voltage is produced at the fifth terminal that is indicative of the Y-position of the touch, the interface circuit comprising:

an analog switch matrix, the analog switch matrix including first, second, third, fourth and fifth terminals which are adapted to be operably connected to the first, second, third and fourth terminals of the first type of touch plane operator input device and to the first, second, third, fourth and fifth terminals of the second type of touch plane operator input device, and the programmable analog switch matrix comprising a plurality of switches that define a plurality of different configurations of the programmable switch matrix;

an analog-to-digital converter, wherein if the interface circuit is connected to the first type of touch plane operator input device, then the analog-to-digital converter receives analog input data by way of the analog switch matrix from at least two of the first, second, third and fourth terminals of the first type of touch plane operator input device and digitizes the analog input data to produce digital input data, wherein if the interface circuit is connected to the second type of touch plane operator input device, then the analog-to-digital converter receives analog input data by way of the analog switch matrix from at least one of the first, second, third, fourth and fifth terminals of the second type of touch plane operator input device and digitizes the analog input data to produce digital input data; and

wherein, in the plurality of different configurations, the plurality of different switches establish different connections with the touch plane operator input device to sense impedance characteristics of the touch plane operator input device, thereby permitting the interface circuit to be used to distinguish the touch plane operator input device as being either the first type of touch plane operator input device or the second type of touch plane operator input device; and

wherein, if the interface circuit is connected to the first type of touch plane operator input device, then the first, second, third and fourth terminals are connected to the first X-axis bus bar, the second X-axis bus bar, the first Y-axis bus bar, and the second Y-axis bus bar, respectively.

17. An interface circuit according to claim 16, wherein the analog switch matrix comprises at least twelve analog switches.

18. An interface circuit according to claim 16, wherein the analog switch matrix is located on a system-on-chip integrated circuit chip, and wherein the integrated circuit chip also has a microprocessor located thereon.

19. An industrial control system comprising:

(A) a plurality of input and output devices;

(B) a communication network;

(C) a control system, the control system being coupled to the communication network and executing a user program to control output status of the plurality of output devices based on input status information from the plurality of input devices;

(D) an operator interface, the operator interface further including

(1) a touch screen including

(a) a display, the display displaying the input and output status of at least a portion of the plurality of input and output devices, and

(b) a touch screen sensor system, and

(2) an integrated circuit, the integrated circuit including

(a) an analog switch matrix, the analog switch matrix being coupled to the touch screen sensor system, the analog switch matrix having a plurality of different configurations, the analog switch matrix receiving an input and selectively supplying the input to the touch screen sensor system based on the configuration of the analog switch matrix to identify a type of touch screen connected to the analog switch matrix,

(b) a digital signal processor, the digital signal processor determining the touch screen type based on the response of the touch screen to the input in the plurality of different configurations of the analog switch matrix, and

(c) a communication network interface, the communication network interface coupling the operator interface to the communication network, and

wherein the integrated circuit senses an impedance across first and second terminals of the touch plane operator input device and processes the sensed impedance to identify the type of touch plane operator input device connected to the interface circuit, and wherein the interface circuit is capable of identifying at least three of the following types of touch plane operator input devices;

4-wire touch plane operator input devices, 5-wire touch plane operator input devices, 7-wire touch plane operator input devices, and 8-wire touch plane operator input devices.

20. An industrial control system according to claim 19, wherein the control system and the operator interface are provided in a single integrated package.

21. An industrial control system according to claim 19, wherein the control system is provided in the form of a rack mounted programmable control system.

22. An internet access device comprising:

(A) a touch plane operator input device, the input device including an input device sensor system;

(B) a display, the display displaying information received from the internet; and

(C) an integrated circuit, the integrated circuit including

(1) an analog switch matrix, the analog switch matrix being coupled to the input device sensor system, the analog switch matrix having a plurality of different configurations, the analog switch matrix receiving an input and selectively supplying the input to the input device sensor system based on the configuration of the analog switch matrix to identify a type of touch plane operator input device connected to the analog switch matrix,

(2) a digital signal processor, the digital signal processor determining a touch plane operator input device type based on the response of the input device sensor system to the input in the plurality of different configurations of the analog switch matrix, and

(3) a communication network interface, the communication network interface coupling the internet access device to the internet, and

wherein the integrated circuit senses an impedance across first and second terminals of the touch plane operator input device and processes the sensed impedance to identify the type of touch plane operator input device connected to the interface circuit, and wherein the interface circuit is capable of identifying at least three of the following types of touch plane operator input devices;

4-wire touch plane operator input devices, 5-wire touch plane operator input devices, 7-wire touch plane operator input devices, and 8-wire touch plane operator input devices.

23. An internet device according to claim 22, wherein the touch plane operator input device and the display in combination comprise a touch screen.

24. An internet device according to claim 22, wherein the touch plane operator input device is a touch pad.